Karyotypic Differences Between Two Species ofPomatoceros, P. TriqueterandP. Lamarckii(Polychaeta: Serpulidae)

Autor: P.L. Pascoe, L.R.J. Dixon, D.R. Dixon
Rok vydání: 1998
Předmět:
Zdroj: Journal of the Marine Biological Association of the United Kingdom. 78:1113-1126
ISSN: 1469-7769
0025-3154
DOI: 10.1017/s0025315400044362
Popis: Consistent with most other closely-related polychaete species which have been analysed cytogenetically to-date,Pomatoceros triqueterandP. lamarckiishare an identical chromosome number (2n=24) and have a number of other karyotypic features in common. However, commensurate with their separate species status, their karyotypes differ at least in four chromosome positions as a result of structural chromosomal rearrangements. With a rDNA probe using the FISH technique, we have been able to demonstrate that the nucleolar organizer region (NOR) occurs at the same site on the same pair of chromosomes in the two species, which indicates that an inversion event is unlikely to have been the cause of the species variation in this particular case. Taken together, these karyotypic differences may be indicative of a chromosomal barrier to the formation of fertile offspring; an important feature for maintaining species integrity where the two forms occur sympatrically, such as in parts of south-west England.
Databáze: OpenAIRE